Biogeographical variation on craniomandibular morphology in pallas’s squirrel \(\textit{Callosciurus erythraeus}\) (Pallas, 1779) (Rodentia: Sciuridae) in Vietnam

Different forest vegetations provide herbivorous small mammals with different resources, forcing adaptation since food habits depend on available resources. We expect differences in vegetation to be reflected the size and shape of skull mandible as a result potentially feeding Therefore, we analyzed craniomandibular characteristics Pallas’s squirrel (Callosciurus erythraeus) Vietnam. This species commonly occurs Vietnam, making it good model for examining morphological type. morphologically skulls mandibles 156 specimens collected from 31 localities Vietnam 1960 present. Principal component analysis showed that females occurring tropical lowland evergreen rain were clearly separated those other vegetations.